JP7373520B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device for controlling the operation of a vehicle.

2. Description of the Related Art Vehicles such as automobiles are equipped with a parking mechanism for locking wheels when parked or stopped. When locking the wheels using the parking mechanism on a slope, if the response speed of the actuator is slow after the parking switch is pressed, the engagement of the parking pole with the parking gear will be delayed, causing the vehicle to move slightly downward along the slope of the slope. There is a possibility that a phenomenon (hereinafter referred to as "(vehicle) sliding downhill" in this specification) may occur.

In order to suppress such sliding, Patent Document 1 discloses that whether or not the road is on a slope is determined based on a signal from a gyro sensor, and when it is determined that the road is on a slope, and the brake is on, the vehicle speed reaches a predetermined value ( (threshold value) or less, a control is described in which the motor is controlled and the motor is waited until the parking switch is pressed. In this motor control, the position of the parking gear and the angle at which the parking gear rotates until the actuator moves the parking pole from the unlocked position to the locked position are calculated in advance, and based on this, the parking gear meshes with the parking pole. The drive motor is rotated by applying motor torque so that it is in the position where it is. Due to the rotation of the drive motor in this motor control, the phases of the parking gear and parking pole are matched in advance, so when the parking switch is pressed and the actuator is activated, the parking gear and parking pole mesh, causing the vehicle to slide downwards. can be suppressed.

Japanese Patent Application Publication No. 2009-30637

However, in the above control, as shown in FIG. 7, since the motor control waits while applying torque until the parking switch (P switch) is pressed, if the time t until the parking switch is pressed is long, There is a concern that the motor temperature may become high and torque may not be applied. In addition, assuming that there is a possibility that the correspondence between the rotation angle of the drive motor and the rotation position of the parking gear may deviate, the system learns the rotation position of the parking gear when the vehicle power is turned on and drives the motor. The correspondence between the rotation angle of the parking motor and the rotation position of the parking gear is corrected, which may increase the cost of the control configuration.

In view of the above problems, the present invention provides a vehicle control device that can suppress the sliding of a vehicle when parking on a slope without causing problems due to temperature rise of the drive motor and without increasing the cost of the control configuration. The purpose is to provide.

In order to solve the above problems, a vehicle control device (1) according to the present invention includes a drive motor (8) for driving a vehicle, a drive shaft ( 22 ) connected to the drive motor (8), A parking gear ( 24 ) fixed to the drive shaft (22), a parking pole (40) meshing with the parking gear (24), and a parking lock operator (58) are operated to lock the parking pole (40) into the parking gear. an actuator (44) that engages with the drive shaft (24) to move the drive shaft ( 22 ) between a locking position and an unlocking position; a slope detection means (56) that detects the slope of the vehicle (2); and a drive motor. After the rotation angle detection means (60) detects the rotation angle of (8) and the actuator (44), the drive motor (8) is rotated at a predetermined angle according to the slope detected by the slope detection means (56). It is characterized by comprising a motor angle control means (48) for rotating the motor.

According to the vehicle control device according to the present invention, regardless of whether there is a phase shift between the parking gear and the parking pole, motor torque is applied after the actuator is activated to rotate the motor for driving at a predetermined angle. This prevents the motor from becoming hot, and eliminates the need for phasing and learning processes between the parking gear and the parking pole, so it is possible to suppress slippage when parking on a slope without increasing the cost of the control configuration.

Further, in the above vehicle control device, it is preferable that the predetermined angle is the maximum angle (α _max ) at which the parking gear (24) rotates until it meshes with the parking pole (40). According to this, by setting the predetermined angle to the maximum angle, it is possible to reliably obtain an in-gear state in which the parking gear meshes with the parking pole by simple control.

Further, in the above vehicle control device, the motor angle control means (48) calculates the motor torque necessary to rotate the parking gear (24) by a predetermined angle, sets this as a target torque, and achieves the target torque in a predetermined time. It is preferable to add the motor torque to reach the desired value. According to this, highly accurate control can be performed by monitoring the relationship between the applied amount of motor torque and the cumulative angle.

Further, in the above vehicle control device, the motor angle control means (48) controls the parking gear (24) when the rotation angle of the drive motor (8) does not increase for a certain period of time in response to an increase in motor torque. (40) It is preferable to determine that the gears are engaged and terminate the control. According to this, the time for motor angle control can be shortened.

Further, in the above vehicle control device, the vehicle speed (v) is detected after the parking lock operator (58) is operated, and based on the detected vehicle speed, it is determined whether or not to permit operation of the actuator (44). It is preferable to include parking operation permission determining means (48) for making this determination. According to this, unnecessary parking operations can be prevented when the vehicle is moving on a slope.

Further, in the above vehicle control device, after the parking operation is permitted by the parking operation permission determination means (48) and the actuator (44) is activated, the motor angle is controlled based on the slope detected by the slope detection means (56). It is preferable to include motor angle control execution determination means (48) for determining whether or not to execute motor angle control by means (48). According to this, it is possible to prevent vehicle behavior that the driver does not expect, such as excessive rolling (referring to a phenomenon in which the vehicle slightly moves upward along the slope of a slope; the same applies hereinafter).

According to the present invention, it is possible to suppress the vehicle from sliding down when parking on a slope without causing problems due to the temperature rise of the drive motor and without increasing the cost of the control configuration.

1 is a schematic configuration diagram of a vehicle equipped with a vehicle control device according to an embodiment of the present invention. FIG. 2 is a control block diagram forming part of a vehicle control device. FIG. 3 is a diagram showing a specific meshing state of a parking gear and a parking pole in the vehicle control device. FIG. 2 is a schematic diagram for explaining the force relationship that acts on a vehicle on a slope. 2 is a flowchart illustrating a control operation performed by the vehicle control device to suppress skidding. 5 is a timing chart showing a control operation for suppressing sliding by the vehicle control device. 3 is a timing chart for explaining problems in the conventional technology.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a vehicle equipped with a vehicle control device according to an embodiment of the present invention. As shown in the figure, a vehicle 2 that is a hybrid vehicle includes an engine 4, a generator 6, a traction motor 8 that is a drive motor, a differential device 10, a parking mechanism 12, and the like. A gear 16 fixed to the drive shaft 14 of the engine 4 meshes with a gear 20 fixed to the shaft 18 of the generator 6. A parking gear 24 of a parking mechanism 23 is fixed to a drive shaft 22 connected to the rotor of the traction motor 8, and a transmission gear 28 meshing with a gear 26 rotationally driven by the engine 4 is fixed. The transmission gear 28 meshes with an idler gear 30, and a gear 32 coaxially fixed with the idler gear 30 meshes with a final gear 34 of the differential device 10. Reference numeral 36 is an axle (rotary shaft) that transmits power from the differential device 10 to the left and right drive wheels 38.

FIG. 2 is a control block diagram forming part of the vehicle control device. Traction motor 8, parking mechanism 12, vehicle speed sensor 54 shown in FIG. 2, tilt angle detection sensor 56, P switch (operator for parking lock) 58, resolver (rotation angle detection means) 60, brake sensor 62, electronic control unit 46 and the like constitute the vehicle control device 1 according to this embodiment.

FIG. 3 is a diagram showing a specific meshing state of the parking gear and the parking pole in the vehicle control device. As shown in FIGS. 1 and 3, the parking mechanism 12 includes a parking gear 24, a parking pole 40 that meshes with the parking gear 24, and moves in the direction of arrow X in FIG. It has a parking rod 42 that engages with the drive shaft 22 to move the drive shaft 22 between a locking position and an unlocking position, and an actuator 44 that drives the parking rod 42 in the same direction.

As shown in FIG. 2, the vehicle control device 1 includes a hybrid electronic control unit (hereinafter abbreviated as electronic control unit) 46 that controls the entire vehicle. The electronic control unit 46 includes a CPU (Central Processing Unit) 48, a ROM (Read Only Memory) 50 that stores processing programs, etc., a RAM (Random Access Memory) 52 that temporarily stores data, and an I/O module (not shown). It is configured as a microcomputer with /O interface and the like. A vehicle speed sensor 54, a tilt angle detection sensor 56, a P switch 58, a resolver 60, and a brake sensor 62 are connected to the electronic control unit 46. The traction motor 8 is connected to an electronic control unit 46 via a motor ECU (motor electronic control unit) 7.

The vehicle speed sensor 54 detects the vehicle speed v of the vehicle 2 and outputs a signal corresponding to the detected vehicle speed v to the CPU 48 of the electronic control unit 46. The CPU 48 functions as a parking operation permission determination unit that determines whether or not to permit operation of the actuator 44 based on the value of the vehicle speed detected by the vehicle speed sensor 54. The tilt angle detection sensor 56 as a slope detection means is composed of an acceleration sensor, a gyro sensor, etc., and detects the gravitational acceleration of the vehicle 2 in the horizontal and vertical directions, and sends a signal corresponding to the detected gravitational acceleration to the electronic control unit 46. Output to CPU 48. The CPU 48 functions as a motor angle control means that rotates the traction motor 8 by a predetermined angle according to the gradient detected by the inclination angle detection sensor 56 after the actuator 44 is activated.

The P switch (parking switch) 58, which is a parking lock operator, outputs a signal for operating the actuator 44 to the CPU 48 of the electronic control unit 46 when pressed by the driver of the vehicle. The CPU 48 functions as a motor angle control execution determination unit that determines whether or not to execute motor angle control by the motor angle control unit based on the slope detected by the tilt angle detection sensor 56 after the actuator 44 is activated. . The resolver 60 serving as rotation angle detection means detects the rotation angle of the traction motor 8 and outputs the detected angle to the CPU 48 of the electronic control unit 46. The brake sensor 62 detects whether a brake pedal (not shown) is on or off, and outputs a signal corresponding to the detected state to the CPU 48 of the electronic control unit 46.

As shown in FIG. 3, the parking pole 40 is rotatably supported around a rotating shaft 66, and is pressed and rotated by the parking rod 42 (see FIG. 1) as the parking rod 42 (see FIG. 1) moves. It is composed of Recesses 24a are formed in the parking gear 24 at equal intervals in the circumferential direction, and the drive shaft 22 is locked when the projections 40a of the parking pole 40 engage (mesh) with the recesses 24a. When the traction motor 8 is rotated by applying motor torque with the brake on, the parking gear 24 is always in gear within an angle α corresponding to the angle between its teeth, and depending on the timing of meshing with the parking pole 40, the parking gear 24 is in gear at a maximum angle α. There is a possibility of _max rotation. That is, for example, when the angle α is 60°, α _max =60°. Therefore, in this embodiment, α _max is set as a predetermined angle until the parking gear 24 is reliably brought into gear. Note that FIG. 1 schematically shows the parking gear 24 and the parking pole 40.

FIG. 4 is a schematic diagram for explaining the force relationship that acts on the vehicle on a slope. As shown in the figure, the weight of the vehicle 2 is M [kg], the tire diameter is R [m], the slope slope (climbing slope) is θ [deg], and the stiffness of the drive shaft 36 by left and right combination is k [Nm]. /deg], the torsional angle of the drive shaft 36 is β[deg], the torsional force of the drive shaft 36 indicated by the upward arrow is kβ/R, the sliding force indicated by the downward arrow is Mgsinθ, and the torsional angle of the drive shaft 36 is β=Mgsinθ/k. Dr/sh in the figure means drive shaft. If the parking brake is not applied after the parking mechanism 12 locks the parking brake, the drive shaft 36 is twisted by an angle β after the brake is turned off, depending on the vehicle weight, the slope of the slope, the tire diameter, and the rigidity of the drive shaft 36. If no control is performed and the parking brake is not applied, the vehicle will slide down by a distance expressed by the following equation (1). In equation (1), i is the ratio of the rotation speed of the axle shaft 36 to the rotation speed of the drive shaft 22.

The control operation of the vehicle control device 1 of this embodiment for preventing this sliding down will be explained with reference to FIGS. 5 and 6.

FIG. 5 is a flowchart showing a control operation performed by the vehicle control device to suppress the vehicle from sliding downward. Moreover, FIG. 6 is a timing chart showing a control operation for suppressing sliding down by the vehicle control device. As shown in FIG. 5, the CPU 48 first determines whether the brake is on based on a signal from the brake sensor 62 (step S1). If the brake is on (YES in step S1), it is determined whether the P switch 58 has been pressed by the driver (step S2). If it is determined that the brake is off (NO in step S1), the process returns to step S1. If it is determined that the P switch 58 has been pressed (YES in step S2), the CPU 48 functions as a parking operation permission determination means and makes a parking operation permission determination as to whether or not to permit operation of the actuator 44 (step S3). ). If it is determined that the P switch 58 is not pressed (NO in step S2), the process returns to step S2. Parking operation permission determination is made based on whether the vehicle speed is less than a predetermined speed v. That is, the CPU 48 compares the vehicle speed detected by the vehicle speed sensor 54 with a predetermined speed v stored in the ROM 50 in advance. If the detected vehicle speed is equal to or higher than the predetermined speed v (NO in step S3), the process returns to step S3. If the detected vehicle speed is less than the predetermined speed v, the CPU 48 transmits an activation signal to the actuator 44 to permit the actuator 44 to operate (step S4). As shown in FIG. 6, there is a response delay after the P switch 58 is turned on until the actuator 44 is activated.

Next, the CPU 48 functions as a motor angle control execution determination means, and after the actuator 44 is activated, the motor angle control means (CPU 48) executes motor angle control based on the gradient detected by the inclination angle detection sensor 56. It is determined whether or not (step S5). That is, the CPU 48 compares the gradient detected by the inclination angle detection sensor 56 with a predetermined gradient d stored in advance in the ROM 50, and if the detected gradient is greater than or equal to the predetermined gradient d, the traction motor 8 is tilted. "TRC angle control" is started to rotate by a predetermined angle according to the slope detected by the angle detection sensor 56 (step S6). In FIG. 6, TRC angle control is indicated as motor control. If the detected gradient is less than the predetermined gradient d (NO in step S5), the process returns to step S5. In the TRC angle control, after the actuator 44 is activated, the traction motor 8 is rotated in the opposite direction to the direction in which the vehicle 2 slides down, and the amount by which the vehicle 2 slides down is reduced to the amount expressed by the following formula (2). .

In order to rotate the parking gear 24 by a predetermined angle while the brake is on, a torque T _TRC of the traction motor 8 expressed by the following equation (3) is required. As shown in FIG. 6, the torque is 0 at the start of TRC angle control. The CPU 48 as a motor angle control means calculates the motor torque required to rotate the parking gear 24 by a predetermined angle using equation (3), sets this as a target torque, and adjusts the motor torque so that the target torque is reached in a predetermined time. are added.

Next, the CPU 48 as a motor angle control means monitors the cumulative value of the detected angle of the traction motor 8 from the resolver 60, and determines whether a predetermined angle α _max has been reached (step S7). When the predetermined angle α _max is reached, the parking gear 24 is assumed to be in gear and the TRC angle control is ended. If the predetermined angle α _max has not been reached (NO in step S7), it is determined whether the cumulative angle does not increase in response to an increase in motor torque for a certain period of time n (whether there is a certain period of time n). (Step S8) If it is determined that the cumulative angle does not increase for a certain period of time n (YES in Step S8), it is determined that the parking pole 40 has engaged with the parking gear 24 (in-gear), and the TRC End angle control. In this case, in-gear is established before the predetermined angle α _max is reached. That is, the time it takes for parking gear 24 to shift into in-gear becomes shorter than a predetermined time. If the time during which the cumulative angle does not increase does not continue for a certain period of time (NO in step S8), the process returns to step S8.

As mentioned above, the amount of skidding can be reduced by TRC angle control, but it is undesirable for the driver to experience unexpected behavior such as excessive skidding, so in the condition range expressed by equation (4) below, In step S5, the CPU 48 does not permit execution of TRC angle control. Thereby, there is no risk of giving the driver unexpected surprise or anxiety.

As described above, in the vehicle control device 1 of the present embodiment, the TRC angle is set such that the parking gear 24 is reliably brought into gear, without adjusting the phases of the parking gear and the parking pole in advance by rotation of the traction motor as in the prior art. Since the control (motor control) is performed, the parking gear 24 can be reliably brought into gear within a predetermined angle regardless of the presence or absence of a phase shift between the parking gear 24 and the parking pole 40. Therefore, motor control can be started after actuation of the actuator 44, and there is no need to wait while applying motor torque until the P switch 58 is pressed as in the prior art. Thereby, there is no possibility that the motor temperature will become high and torque cannot be applied. In addition, there is no need to rotate the traction motor 8 to align the parking gear 24 and the parking pole 40 in advance, and there is no need for a learning process. can be suppressed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various changes can be made within the scope of the claims and the technical idea described in the specification and drawings. is possible. For example, in the above embodiment, the case where the vehicle 2 is parked on an uphill slope has been described, but the same effect can be obtained when the vehicle 2 is parked on a downhill slope.

1 Vehicle control device 2 Vehicle 8 Traction motor (drive motor)
22 Drive shaft 24 Parking gear 40 Parking pole 44 Actuator 46 Hybrid electronic control unit 48 CPU (motor angle control means, parking operation permission determination means, motor angle control execution determination means)
56 Tilt angle detection sensor (gradient detection means)
60 Resolver (rotation angle detection means)
n fixed time α _max predetermined angle (maximum angle)

Claims (5)

a drive motor for driving the vehicle;
a drive shaft connected to the drive motor;
a parking gear fixed to the drive shaft;
a parking pole that meshes with the parking gear;
an actuator that moves the parking pole between a lock position and an unlock position in which the drive shaft is locked by meshing with the parking gear by operating a parking lock operator;
slope detection means for detecting the slope of the vehicle;
rotation angle detection means for detecting the rotation angle of the drive motor;
Motor angle control means for rotating the drive motor by a predetermined angle according to the slope detected by the slope detection means after the actuator starts the operation of moving the parking pole to the lock position;
Equipped with
The motor angle control means calculates a motor torque necessary to rotate the parking gear by the predetermined angle, sets this as a target torque, and adds the motor torque so that the target torque is reached in a predetermined time. go
A vehicle control device characterized by: The vehicle control device according to claim 1, wherein the predetermined angle is a maximum angle at which the parking gear rotates until it meshes with the parking pole. The motor angle control means determines that the parking gear is engaged with the parking pole and ends the control when there is no increase in the rotation angle of the drive motor for a certain period of time in response to an increase in the motor torque. The vehicle control device according to claim 1 or 2. The vehicle is characterized by comprising parking operation permission determination means that detects a vehicle speed after the parking lock operator is operated and determines whether or not to permit the operation of the actuator based on the detected vehicle speed. The vehicle control device according to any one of claims 1 to 3. After the parking operation is permitted by the parking operation permission determining means and the actuator starts the operation, whether or not the motor angle control means executes motor angle control based on the slope detected by the slope detection means. 5. The vehicle control device according to claim 4 , further comprising motor angle control execution determining means for determining .

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